We were sad to hear the news that _______ eight Chinese peacekeeping policemen were killed in ______ Haiti earthquake.  

A．the; /

B．/; the

C．the; a

D．an; the

证券：就是记载和代表一定权利的文书，即用以证明证券的持有人，有权按照证券所载的内容，享有相应权益的一种赁证。　　根据上述定义，下列不属于证券的是( )。

A．股票

B．国库券

C．合同

D．支票